Improvement in bottoms of wash-boilers



UNITED STATES PATENT OFFICE.

CHARLES BURNHAM, OF SPRINGFIELD, MASSACHUSETTS IMPROVEMENT IN BOTTOMS OFWASH-BOILERS.

Specification forming part of Letters Patent No. 43,287, dated June 28,1864.

To all whom it may concern: t

Be it known that I, GHARLEs BURNHAM, of Springfield, in the county ofHam pden and State of Massachusetts, have invented a new and usefularticle ot' manufacture-to Wit, a corrugated bottom for boilers, made ofsheet metal, the corrugations not covering the whole surface of thebottom, but leaving a lip or :margin plain, by means of which theartisan is enabled to make a tirm and smooth seam or lock to the body ofthe boiler-ot' Which the following is a specification.

The usefulness of my invention consists, fst, in providing a bottom,Which will not sag and bond out of shape from use, as occurs where plainbottoms are used; and, second, in affording a larger heating-surfacethan is g ven by a plain bottom. The corrugations of any desiredconfiguration are produced by dies, a distinct set being necessary forevery size and every variety ot' shape in which the article is made. Thedies are'niade so much smaller than the bottom as to leave a smoothandplainlip Vor margin surrounding the corrngated portion of the bottom.The bottom, having been corrugated by the use of the dies, is fastenedto the body of the boiler or other vessel by double-seaming, or in anyother apboilers, made of sheet metal and corrugated,

but with a plain margin or lip surrounding the corrugations, ashereinbefore sot forth.

CHAS. B URNHAM.

Witnesses:

E. MORGAN, A. L. SOULE.

